The embodiments relate to a back light unit, and more particularly, to a back light unit having a plurality of light emitting device assemblies.
A liquid crystal display, which is a kind of passive flat panel display, used in computer monitors, liquid crystal display (LCD) televisions, mobile communication terminals, etc., does not emit light itself. For this reason, the liquid crystal display selectively projects illumination light irradiated from the outside to form an image.
To this end, a back light unit to irradiate light is mounted at the inner rear of the liquid crystal display.
Based on the disposition of light emitting devices, a back light unit is classified as a direct light type back light unit or an edge light type back light unit.
In the direct light type back light unit, light emitting devices are disposed at a light guide plate provided at the rear of a liquid crystal panel to irradiate light toward the rear of the light guide plate. In the edge light type back light unit, light emitting devices are disposed at the side of a light guide plate to irradiate light toward the side of the light guide plate.
In a conventional back light unit, a single light emitting device array or a plurality of light emitting device arrays are covered by a single light guide plate. If a portion of the light guide plate is defected, therefore, it is necessary to replace the entirety of the light guide plate with a new one.
In particular, if a portion of the surface of the light guide plate is scratched, stained or deformed, the brightness or darkness of light on a portion of a screen of a display corresponding to the scratched, stained or deformed portion of the surface of the light guide plate is considerably different from the brightness or darkness of light at the remaining portions of the screen of the display. In order to solve such a problem, therefore, it is necessary to replace the entirety of the light guide plate with a new one.
Meanwhile, for a display having a large-sized screen, the size of a light guide plate is increased in proportion to the size of the screen. In manufacturing a back light unit using such a large-sized light guide plate, assembly is troublesome and too much time is needed.